Tóm tắt:

Fly ash utilization in concrete as partial replacement of cement is gaining importance day by day. In Vietnam, fly ash has been used to as roller compacted concrete of Son La hydroelectricity, rural road concrete and unburnt bricks. However, they have not been used in the rock/soil support of underground coal mines. Now, concrete insert plates with steel arches are the biggest proportion of the type of current structural support in underground mining (about 70÷80%). Concrete insert plates is one part of the concrete insert plates are responsible for closing the gap between the SVP steel frames in drift and the dug evenly distributing the pressure of rock and soil on SVP steel frames, preventing roof landslides and sidewalls. This paper studies the use of fly ash in concrete, cement is replaced partially by fly ash in underground construction concrete. In this experimental work concrete mix prepared with replacement of fly ash by 0%, and 20%. Effect of fly ash on compressive strength and flexural strength of underground construction concrete are studied. To study the impact of partial replacement of cement by fly ash on making concrete insert plate of SVP steel frame in undergound mines.